NAOMI Cab - two problems - maybe power related?

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witchfinder
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NAOMI Cab - two problems - maybe power related?

Post by witchfinder »

I've got two issues with my NAOMI cab which may or may not be related...

1. The monitor goes dead intermittently. Sometimes it doesn't come on at all when I power the cab on. Sometimes it will power on but then goes off with a 'click' after 10-15 minutes. Sometimes it will stay on for hours with seemingly no issue at all!

2. On some games I am getting a 'JAMMA I/O not found' error. Sometime immediately on startup, but sometimes the game will load up and play for a bit before it occurs.

Could both these issues be related to the PSU? I've read that the JAMMA I/O one may be due to inconsistent 5v...

I don't know much about how/where to test voltages in a NAOMI so any advice would be welcomed! :)
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grantspain
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Re: NAOMI Cab - two problems - maybe power related?

Post by grantspain »

sounds like two different issues to me,what monitor is in the cab?
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Re: NAOMI Cab - two problems - maybe power related?

Post by witchfinder »

I think it's a Nanao MS9 but it could be a Sanwa. I'll have to get the back off the cab and check...
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Re: NAOMI Cab - two problems - maybe power related?

Post by Paulie »

witchfinder wrote:I don't know much about how/where to test voltages in a NAOMI so any advice would be welcomed! :)
Test Naomi voltages like this
Locate CN1 on the mobo (the white 8 pin JST connector)
Set your multi meter
Insert the black probe into any pin from 5 to 8 (GND) and the red probe into pin 2 (+3.3V), check the voltage and then proceed onto pin 3 then onto pin 4

Top Row Left to right
Pin 1: N/C
Pin 2: +3.3V
Pin 3: +5V
Pin 4: +12V

Bottom Row
Pin 5~8: GND

I took a photo ages ago as to where on the mobo I'm talking about here http://forum.arcadeotaku.com/viewtopic.php?t=20528 as I always think pictures speak better than words.
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Re: NAOMI Cab - two problems - maybe power related?

Post by witchfinder »

I opened the cab up this afternoon and the monitor is actually an MS-2932.

I haven't checked any of the power yet - would I at least be correct in thinking that the JAMMA I/O issue could be power related? It seems to come and go, suggesting it's not an error with the hardware.
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Re: NAOMI Cab - two problems - maybe power related?

Post by witchfinder »

Finally got around to testing the power and having a look at the monitor more closely...

Checked the inputs to the motherboard as suggested and they all seem acceptable - 3.42v, 5.14v and 11.96v - so it looks like that isn't the issue. I had a closer look at the I/O board and reseated all the connections but it made no obvious difference. Here's a pic in case anyone can spot anything wrong. Both LEDs light up red.

Image

So would I be right in thinking I'm going to need a replacement I/O board? Is there any chance of getting this one repaired?

As for the monitor, I looked at the chassis more closely and when the screen goes off, there is no neck glow. I checked the power going into the chassis and it is getting 110v up to this point:

Image

So I guess something is going wrong intermittently on the chassis itself. Any ideas?
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